Study on a novel polyester composite nanofiltration membrane by interfacial polymerization. II. The
Study on a novel polyester composite nanofiltration membrane by interfacial polymerization. II. The
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DOI：
10.1016/j.memsci.2010.09.015
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发表时间：
2010-12
期刊：
影响因子：
--
通讯作者：
Beibei Tang;Chenglong Zou;Peiyi Wu
中科院分区：
文献类型：
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作者：
Beibei Tang;Chenglong Zou;Peiyi Wu
采用均苯三甲酰氯（TMC）与三乙醇胺（TEOA）和N-甲基二乙醇胺（MDEOA）在水相中通过界面聚合制备了复合膜。考察了水相中LiBr对复合膜性能和表面形貌的影响。对于单体TEOA，复合膜的纯水通量随着LiBr含量的增加而增加，在LiBr含量为3%时达到最大值，然后下降。然而，盐截留率的极值随着LiBr的含量变化到1%（转折点）而起作用，在该转折点处膜显示出最低的盐截留率。复合膜性能随LiBr含量的变化是两种因素竞争的结果。一种是Li+离子与醇胺中的羟基氧原子相互作用，导致水相中OH基团的密度和反应活性增加，从而形成致密的复合膜皮层。另一个因素是Li+离子与TMC的羰基络合，导致TMC的酰氯基团优先水解，从而形成亲水、疏松的表面层。通过对另一种单体MDEOA的研究，进一步证实了LiBr在复合膜形成中的作用。通过反应系数、接触角、流动电位、扫描电镜和原子力显微镜对LiBr存在下复合膜形成的分析进行了验证。
Composite membranes were prepared by interfacial polymerization of trimesoyl chloride (TMC) with (i) triethanolamine (TEOA), and (ii) N-methyl-diethanolamine (MDEOA) on addition of various contents of LiBr in aqueous phase. The influence of LiBr in aqueous phase on the composite membrane performance and surface morphologies was investigated. For monomer TEOA, the pure water flux of composite membrane enhanced as the LiBr content increased and it reached a maximum at 3% of LiBr, then decreased. However, the extreme value of the salt rejection functioned with the content of LiBr changed to 1% (a turning point), at which the membrane displayed a lowest salt rejection. The change in performance of the composite membrane with the content of LiBr was due to the competition of two factors. One was the interaction of Li+ion with the hydroxyl oxygen atom of alcohol amine, which could induce an increase in the density and reactivity of OH groups in the aqueous phase, forming a dense skin layer of the composite membrane as a result. The other factor was the complexation of Li+ion with the carbonyl in TMC, causing the acid chloride group of TMC preferring to hydrolyze which could induce to construct a hydrophilic and loose surface layer. The role of LiBr in the formation of the composite membrane was further testified by investigating another monomer MDEOA. The analysis of the composite membrane formation in the presence of LiBr was validated by reaction coefficient, contact angle, streaming potential, SEM, and AFM.